POS1301 MORTALITY AND CAUSES OF DEATH AMONG FINNISH PATIENTS WITH SYSTEMIC SCLEROSIS
Authors: S. Kortelainen, M. Käyrä, T. Rissanen, J. Paltta, L. Pirilä, J. Huhtakangas
Journal: Annals of the Rheumatic Diseases (2023)

<h3>Background</h3> Systemic sclerosis (SSc) is a rare rheumatic autoimmune disease, characterized by vasculopathy and fibrosis of the skin and internal organs [1]. Mortality and morbidity of systemic sclerosis is significant. The studies assessing changes in the mortality of SSc are controversial, only minor sign of improvement of prognosis is seen. Among SSc-related causes of death scleroderma renal crisis has become rare and cardiopulmonary causes have become more common. Most of the studies are conducted using either the ACR 1980-criteria or the LeRoy and Medsger -criteria. <h3>Objectives</h3> Aim of this study was to examine mortality and basic causes of death among Finnish patients with systemic sclerosis (SSc) during years 2000- 2020 using the ACR/EULAR 2013 criteria for SSc diagnosis. <h3>Methods</h3> Patients with a diagnostic code of systemic sclerosis (ICD-10 codes beginning with M34) that appeared at least once in their medical records during the years 1996–2018 were identified from the hospital discharge registers of Turku and Oulu University hospitals. False diagnoses and typing errors were excluded. Using ACR/EULAR 2013 criteria and clinical findings, the diagnoses were reclassified and divided into different subsets of the disease. These subsets were diffuse cutaneous systemic sclerosis (dcSSc), limited cutaneous systemic sclerosis (lcSSc), over-lap SSc (diagnosis of other rheumatic disease fulfilled simultaneously) and sine scleroderma (SSc without skin affision). The clinical data was collected to the end of year 2020. The death certificates including the basic and imminent causes of death were obtained from Statistics Finland until August 2021. By examining patient records and death certificates the basic cause of death for each subject was re-evaluated.The study data were collected and managed using REDCap electronic data capture tools hosted at the University of Turku. <h3>Results</h3> Among 313 SSc patients, 91 deaths occurred between 4/2000- 9/2020. 35 deaths were caused by SSc, 20 by atherosclerosis, 18 by cancer and 18 by other causes. Majority of SSc-related deaths were due to interstitial lung disease (ILD) and pulmonary arterial hypertension (PAH), 13 and 11 deaths respectively. Four deaths were due to scleroderma renal crisis (SRC), three deaths due to gastrointestinal tract involvement, two due to SSc-related myocardial involvement and two due to other SSc-related causes, those were vasculopathy complications. The mean age at dead of patients who died of a SSc-related cause was 65.6 years (SD 12.7, CI= 61.2-70.1) in contrast to patients who died due to other causes was 74.2 years (SD 9.6, CI= 71.5-76.9), the difference was statistically significant (p=0.0006). The median time from SSc diagnosis to death was 4.4 years [IQR 1.5, 11.8] in the SSc-related death group and 10.8 years [IQR 4.7, 17.1] for others, the difference was statistically significant (p=0.0061). Death due to renal crisis occurred fastest, in two months. An ILD related death occurred 11.8 years after and a PAH related death 3.7 years after the SSc diagnosis on average. In females, PAH and ILD were the most common causes of death, both nine of 25 subjects. In males, ILD was the most common cause of death, in four of ten subjects. In the group of dcSSc, the most common cause of death was ILD with five deaths out of twelve. In the group of lcSSc, PAH and ILD were the most common causes of death with both eight of 19 deaths. Four deaths due to SRC were all in the group of dcSSc. Twelve of 23 patients with dcSSc (52%) and nineteen of 60 patients with lcSSc (32%) died due to SSc. <h3>Conclusion</h3> The main finding in our study is the fact, that SSc disease itself is the major cause of death among Finnish SSc patients. Among the SSc related deaths, ILD and PAH were the leading causes of death. The patients who died due to SSc were significantly younger and the time from SSc diagnosis was significantly shorter compared to those who died due to other causes. <h3>Reference</h3> [1]Denton CP, Khanna D. Systemic sclerosis. The lancet. North Amer. 2017;390:1685–99. <h3>Acknowledgements:</h3> NIL. <h3>Disclosure of Interests</h3> Saara Kortelainen Speakers bureau: Boehringer-Ingelheim, UCB, Consultant of: Boehringer-Ingelheim, Markus Käyrä: None declared, Tiia Rissanen: None declared, Johanna Paltta Speakers bureau: UCB, Laura Pirilä Speakers bureau: Abbvie, Boehringer-Ingelheim, Jansen-Cilag, Novartis Finland, Sandoz, Eli Lilly and Swedish Orphan Biovirtum, Consultant of: Abbvie, Boehringer-Ingelheim, Jansen-Cilag, Novartis Finland, Sandoz, Eli Lilly and Swedish Orphan Biovirtum, Johanna Huhtakangas Speakers bureau: Boehringer Ingelheim, Abbvie, Amgen, Novartis, Consultant of: Boehringer Ingelheim, Abbvie, Amgen, Novartis.